I think I need a picture to know what you are talking about
Synonyms help us connect unknown words with known words. For example, one may not know the meaning of the word "nefarious" when used in this context: "The offense was more nefarious than previously thought." If we replace "nefarious" with "evil" or "wretched" the meaning is more comprehensible to those who don't know the meaning of "nefarious": The offense was more evil (wretched) than previously thought."
I hope this helps, I used nefarious as a somewhat uncommon term to better illustrate my point, and to explain why we use synonyms to learn new words. Simply put, synonyms bridge us to the unknown using the known as solid ground build from.
Everything is correct except for number 5, which has two prepositional phrases, "behind the door: and "for her friend."
It was the first painting that showed a fully equipped domestic interior. (Apex)
